Fisahn A, Pike F G, Buhl E H, Paulsen O
MRC Anatomical Neuropharmacology Unit, University Department of Pharmacology, Oxford, UK.
Nature. 1998 Jul 9;394(6689):186-9. doi: 10.1038/28179.
Acetylcholine is vital for cognitive functions of the brain. Although its actions in the individual cell are known in some detail, its effects at the network level are poorly understood. The hippocampus, which receives a major cholinergic input from the medial septum/diagonal band, is important in memory and exhibits network activity at 40 Hz during relevant behaviours. Here we show that cholinergic activation is sufficient to induce 40-Hz network oscillations in the hippocampus in vitro. Oscillatory activity is generated spontaneously in the CA3 subfield and can persist for hours. During the oscillatory state, principal neurons fire action potentials that are phase-related to the extracellular oscillation, but each neuron fires in only a small proportion of the cycles. Both excitatory and inhibitory synaptic events participate during the network oscillation in a precise temporal pattern. These results indicate that subcortical cholinergic input can control hippocampal memory processing by inducing fast network oscillations.
乙酰胆碱对大脑的认知功能至关重要。尽管其在单个细胞中的作用已得到一定程度的详细了解，但其在网络层面的影响却知之甚少。海马体接收来自内侧隔区/斜角带的主要胆碱能输入，在记忆方面很重要，并且在相关行为期间会表现出40赫兹的网络活动。在这里，我们表明胆碱能激活足以在体外诱导海马体中的40赫兹网络振荡。振荡活动在CA3子区域自发产生，并且可以持续数小时。在振荡状态下，主要神经元发放与细胞外振荡相位相关的动作电位，但每个神经元仅在一小部分周期中发放。兴奋性和抑制性突触事件在网络振荡期间均以精确的时间模式参与。这些结果表明，皮层下胆碱能输入可以通过诱导快速网络振荡来控制海马体的记忆处理。
